cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A112121 G.f. A(x) satisfies A(A(A(..(A(x))..))) = B(x) (10th self-COMPOSE of A) such that the coefficients of B(x) consist only of numbers {1,2,3,..,10}, with B(0) = 0.

Original entry on oeis.org

1, 1, -8, 104, -1619, 27437, -482626, 8553639, -149434331, 2527339944, -40748011084, 619534898788, -8892967520397, 124088656925363, -1797865061490547, 28140512084643142, -424643873334235802, 4269156014010214570, 19251023484926369328, -1456780704021544219838
Offset: 1

Views

Author

Paul D. Hanna, Aug 27 2005

Keywords

Examples

			A(x) = x + x^2 - 8*x^3 + 104*x^4 - 1619*x^5 + 27437*x^6 +...
where A(A(A(A(A(A(A(A(A(A(x)))))))))) =
x + 10*x^2 + 10*x^3 + 5*x^4 + 10*x^5 + 5*x^6 + 8*x^7 +...
is the g.f. of A112120.
		

Crossrefs

Programs

  • PARI
    {a(n,m=10)=local(F=x+x^2+x*O(x^n),G);if(n<1,0, for(k=3,n, G=F+x*O(x^k);for(i=1,m-1,G=subst(F,x,G)); F=F-((polcoeff(G,k)-1)\m)*x^k); return(polcoeff(F,n,x)))}